Mothproofing of keratinaceous materials



t d States atent MOTHPROOFING or KERATINACEOUS MATERIALS Lloyd M. Kozlolf, Chicago, Ill., assignor, by direct and mesne assignments, ofseventy percent to Hightower- Morse & Company, Chicago, 111., a corporation of Delaware, ten percent to Bernard Wolnak, Highland Park, and live percent to Joseph 1. Antonow, Chlca'go, Ill.

No Drawing. Filed Dec. 17, 195'], Ser. No. 703,289

4 Claims. (Cl. 8-17) This invention relates to the production of moth resistant products and more particularly relates to the pro- 0.;1Cti011 of moth resistant keratinaceous materials and to methods of producing the same.

It? well known in the art that woolen goods and other materials of a keratinaceous protein nature are subject to attack and damage by insects during prolonged storage. Typical of sneh insects is the common webbing clothes moth, also designated as Tineplabisselliella. The primary destruction by clothes moths is carried out by the larval sta e of. this insec n ich form it y subsist substantially upon a diet of keratinaceous protein, Many methods have been proposed for reducing the damage caused by the larva of the Webbing clothes moth, which include, storage in tightly closed containers such as cedar chests, or the use of solid volatile moth repellent mate rials such as naphthalene or paradichlorobenzene, which are usually stored with the garments to be protected.

It has also been proposed and demonstrated that the use of various insecticidal materials $1 as DDT Or re- 2,945,736 Patented July 19, 1960 ice lseratinaceous material which is relatively free of toxic ingredients.

Another object is the provision of a method for rendering a keratinaceous material moth resistant, which does not aflect the color or appearance of the goods to which it is applied. a

A still further object is the production of amoth resistant fibrous woolen material whose properties are relatively unaffected by heat.

A still further object is the provision of moth resistant woolen goods which are relatively unaffected by and resistant to dry cleaning and washing.

A still further object is the provision of a process for rendering woolen goods resistant to moth damage which is readily integrated in the wool production process.

These and other objects of the present invention will be seen from the following specification and appended claims.

In one embodiment the present invention comprises a keratinaceous material impregnated with a relatively small amount of benzimidazole. It is also contemplated as a part of this invention to provide a method of treating woolen or other keratinaceous material with benzimidazole to produce a moth resistant product.

With reference to the materials to which the broad concept of the present invention is applicable, it should be stated. that. they in lar p y be tanned keratinaceous substances, as described above, which are so charlated chlorinated insecticides results in a substantial re duction in damage to clothing and other materials which are, stored or unused for a substantial. period of time.

While the foregoing methods have been used to advantageunder y n cu tan es. th h v er a n drawba ks h h. n r e -use undes ab e n ma y respects. For example, the use of naphthalene or paradichlorobenz ene as a moth repellent usually results in the saturation of the fibers by the vapors of the repellent so that clothing retaining the characteristic odor thereof is not ready for immediate use after storage for a prolonged period in confined or intimate contact withthese materials without a rather substantial airing out. Furthermore repellents are not suitable for the protection of Woolen carpeting, draperies or the like, which are often subject to moth damage; their eflectiveness is largely dependent upon confinement of their vaporsin relatively small spaces.

With regard to chlorinated insecticides such as DDT, it is well understood that these materials are toxic organic compounds which may be cutaneously absorbed by persons coming into contact therewith for prolonged periods, and they have been criticized for this reason. Other chlorinated insecticides may have staining or other characteristics which render their use inexpedient. Furthermore these, materials (DDT and the. like) are relatively soluble i gan ents nd a e er f re e d y remo d in a s ng e ea g, d r r a m nt is equired...

Accordingly, one, object of the. present invention is the production of keratinaceous materials which are, resistant to. moth damage over a prolonged periodof time.

Another object ofthe present invention is the provision of a process for mothproofing wool and Other; keratinaceous materials which is not detrimental to the physical properties of the goods. 7 V I protein. keratin.

' to materials made wholly from these substances, but also may occur in fabrics containing these materials in conjunction with other fibers which are naturally moth resistant. Particularly it should be understood that this invention is applicable to woolen blends with materials such as nylon, rayon, cotton, or the like. i

, The'substanceutilized in the treatment of woolens and similar material is as described above, benzimidazole. It has been found that by impregnating woolen products. and similar goods with a relatively small amount of henzimidazole, sustained protection against clothes moth larva damage may be obtained.

Generally the concentration of benzimidazole that should be present on the woolen fibers is on the order of at least 0.5 Weight percent. It has been found that woolens treated withbenzimidazole at the above or higher concentrations have prolonged resistance to moth damage. While these concentrations have been found to be eifective, concentrations of as high as 7.5 weight percent may be utilized to more adequately protect the goods thereby impregnated. A most preferred range of concentration which gives substantially complete protection is from 1 to 5 weight percent. Alternatively, the concentration of impregnant may be expressed in terms of weight per unit area. Thus the range of benzimidazole includes from 0.15 to 2.5 milligrams per square centimeter, and a most preferred range from 0.3 to about 1.6 milligrams per square centimeter.

While it is possible to use higher concentrations. of henzimidazole, it should be stated that no particular advantage is achieved thereby and the use of excessive amounts thereof is merely economically inexpedient.

The method of treating the keratinaceous material comprises impregnation of the keratina-ceous substance or fabric with benzimidazole in aqueous solution. impregnation may be carried. out in an aqueous medium for a period of time sufficient to insure the impregnation or adsorptionof a suilicient concentration ofbenzimidazole upon the surfaces of fibers in the woolens or other example, it has been found that aqueous solutions of v benzimidazole containing the latter in a concentration of 1 to 20 milligrams per milliliter are suitable imprege nating solutions for woolen fabrics. The time of resia dence or treatment in such solution may vary, it being understood that the degree of adsorption varies to some extent with the length of treatment, thus periods of time from fifteen minutes to as long as three hours or more may be utilized. While the temperature of the solution is not critical the process is preferably carried out at elevated temperatures substantially above normal room temperature, since the concentration of benzimidazole attainable in aqueous solutions decreases at lower temperature.

Broadly the most preferred temperatures are between 50 and 85 C. More elevated temperatures such as boiling (100 C.) may also be utilized. Of course with temperatures lower than 50 C. the rate of adsorption is impregnated with benzimidazole without the addition of acidic materials and the results, in terms of percent cfficiency, were determined. The term percent efiiciency" relates to the degree of protection achieved by the impregnation and is derived from the ratio of the decrease in the weight of debris from moth larvae damage with respect to the debris produced by moth larvae in an untreated control swatch. The following formula was adopted: Percent efliciency= X 100 wherein: p A is the weight of moth larvae debris from the treated sample B is the weight of moth larvae debris in the untreated control The following table gives the results of the above experiments.

Table EFFECT OF BENZIMIDAZOLE APPLIED FROM SIMULATED ACID DYE BAIH Concentration Benzimldazole Weight 0! Nofoi Adsorbed by Wool Debris, Living Percent Observable Impregnation Bath-Initial Mg." Forms Efflciency Damage (mgJmL) (600 mg.) total mg/cm. Wt.

Percent 2 0. 97 2.9 10.2 3larvee.-. 77 None. in 0.47 1.4 16.5 4larvae.-- 62 None. 5 0.21 0.83 30.5 {22:3 so Varysllght. Untreated Contr l 43.6 {g gfiggg::} Considerable.

"Mg; milligrams.

decreased and a longer impregnation may be required to carried out successfully in substantially neutral or alkaline aqueous solutions, it has been found that the impregnation of benzimidazole on the fibers of the goods so treated is enhanced by carrying out the treatment under acid conditions ranging from a pH of about 1 to about 6. Mineral acids, such as sulfuric or hydrochloric acid, are useful to produce the desired acid conditions as well as acid salts such as Glaubers salt. This characteristic is particularly valuable in that the mothproofing treatment may be carried out simultaneously and in conjunction with wool dyeing operations since many of these dyeing operations are carried out under acid conditions.

The process of the present invention and the resulting product may be more clearly understood by reference to the following examples:

EXPERIMENT Swatches of dirt-free, undyed woolen cloth (7.5 by 6.5 centimeters) weighing 1.5 grams each, were impregnated with benzimidazole. The impregnating bath was an aqueous solution containing benzimidazole in concentrations of from 5 to milligrams per milliliter. In addition to the impregnant, the batch contained 10 percent Na SO -10H O (Glaubers Salt) and 4% sulfuric acid to simulate acid dye bath conditions. The solution was maintained at about 65 C. and at a pH of about 2. The wool swatches were impregnated by soaking for a period of about three hours. Before impregnation, the test swatches were prewet with water for thirty minutes. After impregnation, the swatches were air dried for two days. Each treated swatch was then placed in a test chamber and exposed to the attack of 10 moth larvae for a period of twenty-eight days under constant temperature (80 F.) and humidity conditions. For purposes of comparison, several swatches of wool were From the above data it may be seen that benzimidazole is effective as an impregnant to reduce the incidence of clothes moth larvae damage. As indicated in the table, very slight or no damage was observed in the treated samples. It was found that in the preferred method of treatment (acid bath impregnation) the benzimidazole is considerably more eflicient than when applied under substantially neutral conditions. This factor is beneficial as previously indicated, since it permits impregnation of woolens concomitantly with the dyeing operation which is conventionally carried out under acid conditions.

The impregnation of woolen goods with benzimidazole produces a moth resistant fabric that retains a surprising degree of efiiciency even after several dry cleanings. Thus woolen swatches impregnated with benzimidazole had efiiciencies of 9 9% and of their original value after respectively one and two dry cleaning operations utilizing carbon tetrachloride as the cleaning agent. Benzimidazole also demonstrates valuable properties with respect to resistance to washing.

Tests with benzimidazole applied to wool swatches in conjunction with acid wool dyes such as Chromolan Grey, Alizarine Sapphire SE (Color Index No. 63000), Croceine Scarlet M00 #90 (Color Index No. 27290), and Erie Scarlet B (Color Index No. 22240), indicated no alteration in the potency of benzimidazole or the protection achieved. Likewise the use of alkaline dyes such as Superchrome B (Color Index No. 15705) and the application of benzimidazole to wool fabric in conjunction therewith from alkaline solution gave satisfactory results. For example, wool swatches impregnated with about 0.97 milligram per square centimeter (2.9 weight percent) in conjunction with the above dyes gave a percent efficiency of from about 65% to about 83%.

While the foregoing experiments have indicated an impregnation carried out over a three hour period, it is to all dyes are products of National Aniline Corporation.

be understood that prolonged impregnations are not necessary to produce the products of the present invention. For example, impregnations may be from fifteen to thirty minutes, and by proper adjustment of the con centrations of b'enzimidazole in the impregnating bath the desired deposit of this material may be obtained in the fibers of the wool, or other keratinaceous material. Accordingly the impregnation of the present invention is especially well suited as suggested above for concomitant operation with dyeing procedures. Conventionally the dyeing process may require varying periods of time according to the type of dye utilized and the intensity of color desired.

While the foregoing has been illustrative of the impregnation of the wool from aqueous baths, it is possible to achieve the same purpose by impregnation from organic solvents, aqueous dispersions of organic materials such as emulsions, or by spraying the benzimidazole onto the wool. While benzimidazole has been used in the mothproofing of woolen materials, other keratinaceous protein based materials may be similarly treated. Furthermore, it is possible to utilize other mothproofing materials in conjunction with benzimid-azole to achieve a broad protection and provide mothproofing for a variety of materials.

While several particular embodiments of this invention I claim: 7

l. A method of controlling the larvae of Tineola bisselliella which comprises impregnating the keratinaceous habitat of said larvae with at least about 0.5% of benzimidazole.

2. A method of controlling the larvae of Tineola bisselliella which comprises impregnating the keratinaceous habitat of said larvae with at least about 0.5% of benzimidazole from an aqueous acidic solution maintained at a pH of less than about 2.

- 3. The method of claim 2 wherein the concentration of benzimidazole impregnated in the keratinaceous material is from about 1 to about 5% by weight thereof.

'4. A method of controlling the larvae of Tineola bis sellz'ella which comprises contacting the wool habitat of said larvae with an aqueous solution containing acid wool dyes and benzimidazole wherein said solution is maintained at a pH of less than about 2, to produce a dyed wool containing at least about 0.5% benzimidazole by weight thereof.

References Cited in the file of this patent UNITED STATES PATENTS Martin et al. Mar. 2, 1943 Higgins Sept. 27, 1949 OTHER REFERENCES 7 

4. A METHOD OF CONTROLLING THE LARVAE OF TINEOLA BISSELLIELIA WHICH COMPRISES CONTACTING THE WOOL HABITAT OF SAID LARVAE WITH AN AQUEOUS SOLUTION CONTAINING ACID WOOL DYES AND BENZIMIDAZOLE WHEREIN SAID SOLUTION IS MAINTAINED AT A PH OF LESS THAN ABOUT 2, TO PRODUCE A DYED WOOL CONTAINING AT LEAST ABOUT 0.5% BENZIMIDAZOLE BY WEIGHT THEREOF. 